What type of public speaking requires the participant to give a speech with little or no time for preparation?

The correct answer is impromptu speaking, as this style specifically involves delivering a speech with minimal preparation time. In impromptu speaking situations, the speaker might be given a topic on the spot and is often expected to organize their thoughts and present them coherently within a short timeframe. This can challenge a speaker's ability to think quickly, articulate their ideas clearly, and engage with the audience without the benefit of rehearsal or extensive notes.

Extemporaneous speaking, while related, typically allows for some preparation beforehand. In this format, speakers may have a brief period to organize their thoughts around a given topic and are usually expected to prepare notes or outlines, making it distinct from impromptu speaking. Prepared speaking involves thoroughly rehearsed and planned presentations, often based on a pre-selected topic. Debate requires formal argumentation from opposing sides and often includes significant preparation as well, particularly regarding the research and construction of arguments.

Understanding these distinctions helps clarify the characteristics of each speaking style, highlighting why impromptu speaking is recognized for its spontaneity and immediate engagement.